Head Up The Ass syndrome. Living or acting (especially while driving) in such a way that any sane person would easily conclude that you've clearly got shit for brains.
A class of female currently residing in Terre Haute, Indiana, usually between the ages of 16 and 24. They can be identified by their enthusiastic use of facial cosmetics, skin which is tanned to an excessive degree, and an IQ approximately equal to that of the Hexaprotodon Liberiensis, otherwise known as the Pygmy Hippopotamus.
(Note: Upon exceeding their expiration date, the female will increase in bodily volume at an exponential rate.)